Area Forecast Discussion
Issued by NWS Medford, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KMFR 230800
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
100 AM PDT THU OCT 23 2014

.DISCUSSION...23/00Z NAM/GFS IN.

A FRONT IS NOW PUSHING THROUGH THE MEDFORD CWA. LIGHT TO MODERATE
RAIN IS OCCURRING WITH THE WEAKENING FRONTAL BOUNDARY.
MEANWHILE...BEHIND THE FRONT...THERE IS LOTS OF SHOWER ACTIVITY. A
FEW THUNDERSTORMS MAY MOVE INTO THE COASTAL WATERS LATER THIS
MORNING.

THE LONG WAVE TROUGH REMAINS OFFSHORE WITH STRONG SOUTHWEST FLOW
ALOFT. SHORT WAVES EJECTING FROM THE TROUGH WILL BRING ROUNDS OF
SHOWERS TO THE AREA THURSDAY...BUT MOST OF THE ENERGY IN THE
SHORT WAVES WILL BE DIRECTED TO THE NORTH OF THE CWA. THE SURFACE
FRONT WILL STALL OVER THE SOUTHERN AND EASTERN PORTIONS OF THE
MEDFORD CWA THURSDAY.

RAINFALL AMOUNTS FOR THIS CURRENT STORM SYSTEM HAVE BEEN ADJUSTED
DOWN SOME THROUGH THURSDAY EVENING FOR AREAS INLAND FROM THE
COAST...BUT HAVE LEFT 3 TO 5 INCH AMOUNTS INTACT FOR THE COAST
AND COASTAL MOUNTAIN AREAS...WITH MOST OF THE RAIN THERE EXPECTED
THROUGH 5AM PDT THURSDAY. OTHER AMOUNTS WILL BE 1.3 TO 2.3 INCHES
IN DOUGLAS COUNTY...1-3 INCHES IN JOSEPHINE COUNTY, AND 0.50" TO
1.5" IN JACKSON COUNTY. 0.10" TO 0.50" INCHES WILL FALL IN THE
EAST SIDE VALLEYS...DECREASING FROM WEST TO EAST.

THE OFFSHORE UPPER TROUGH WILL DEEPEN AND START TO SHEAR FRIDAY.
IN RESPONSE A LONG WAVE RIDGE WILL PUMP UP OVER THE INTERMOUNTAIN
STATES...AND THIS WILL LIFT THE FRONT BACK NORTH AS A WARM FRONT
FRIDAY. EXPECT WIDESPREAD LIGHT PRECIPITATION WITH THE FRONT AS IT
MOVES THROUGH THE AREA.

THERE WILL BE A BREAK IN THE PRECIPITATION FRIDAY NIGHT AS THE
WARM FRONT CLEARS TO THE NORTH. CONDITIONS WILL THEN GET QUITE
INTERESTING OFFSHORE AS A LOW WINDS UP UNDER THE SOUTHERN PORTION
OF THE SHEARING TROUGH. THIS LOW WILL DEEPEN AS IT TRACKS NORTH
NORTHEAST INSIDE 130W. THE TRACK AND DEEPENING OF THE LOW WILL BE
CRITICAL AS FAR AS HIGH WINDS AT THE COAST ARE CONCERNED. AT THIS
TIME IT LOOKS LIKE THE LOW WILL TRACK FAR ENOUGH OFFSHORE AND WILL
NOT BE STRONG ENOUGH...AROUND 990 MB...FOR A WARNING ALONG THE
COAST...WHERE THERE WILL BE A SIGNIFICANT OFFSHORE COMPONENT TO
THE WIND. HOWEVER...STORM FORCE WINDS MAY DEVELOP OVER THE OUTER
COASTAL WATERS. WINDS ALOFT COMBINED WITH STRONG SOUTHERLY GRADIENTS
MAY PROVIDE ENOUGH SUPPORT FOR HIGH WINDS IN THE SHASTA VALLEY AND
EAST OF THE CASCADES AROUND SUMMER LAKE.

WIDESPREAD MODERATE PRECIPITATION WILL MOVE ONSHORE SATURDAY
AFTERNOON AND EVENING. SATURDAY NIGHT WILL BE QUITE WET FROM THE
CASCADES WEST WITH LIGHTER PRECIPITATION EAST OF THE CASCADES.

THE SOUTHERN BRANCH SYSTEM WILL MOVE ONSHORE TO THE NORTH
SATURDAY NIGHT AND WHAT`S LEFT OF THE LONG WAVE TROUGH WILL MOVE
ONSHORE SATURDAY NIGHT AND THROUGH THE MEDFORD CWA SUNDAY. EXPECT
SHOWERS TO CONTINUE THROUGH SUNDAY...BUT THEY WILL BE DIMINISHING
WITH TIME.

EXTENDED DISCUSSION FROM THE WEDNESDAY AFTERNOON AFD...MONDAY
THROUGH WEDNESDAY. NUMERICAL MODELS INDICATE ABOUT TWO FRONTAL
SYSTEMS NEXT WEEK WITH MONDAY BEING DRY FOR MOST LOCATIONS AWAY
FROM THE COAST. TIMING OF THE FRONTS NEXT WEEK IS A BIT IN
QUESTION...BUT SUFFICE IT TO SAY THAT THE WEATHER PATTERN DOES
LOOK TO REMAIN ACTIVE WITH A FRONTAL SYSTEM EVERY 2-3 DAYS. THE
OVERALL PARENT TROUGH OVER THE AREA SINKS SOUTHWARD NEXT WEEK...SO
EXPECT SNOW LEVELS WILL LIKELY COME DOWN TO THE 5000 TO 7000 FOOT
RANGE. BTL

&&

.AVIATION...BASED ON THE 23/06Z TAF CYCLE. A FRONT IS PUSHING
INTO THE CASCADES THIS MORNING AND SOUTHEAST THIS AFTERNOON
BRINGING RAIN WHILE BEHIND THE FRONT, SHOWERS WILL MOVE INTO THE
AREA. AREAS OF MVFR TO OCCASIONALLY IFR CIGS/VIS WILL PERSIST OVER
INLAND AREAS WITH THE FRONTAL BAND AS IT PUSHES ACROSS THE
CASCADES AND THEN SOUTHEAST THIS MORNING IN AREAS OF MODERATE
RAINFALL. BEHIND THE FRONT FOR AREAS WEST OF THE CASCADES AND
ALONG THE COAST, EXPECT SHOWERS WITH A MIX OF VFR/MVFR CIGS THIS
MORNING. THEN IN THE AFTERNOON, THE FRONT WILL GRADUALLY PUSH
SOUTHEASTWARD AND LINGER OVER PORTIONS OF NORTHERN CALIFORNIA AND
EXTREME SOUTHEAST OREGON WITH SHOWERS CONTINUING BEHIND IT. DURING
THE AFTERNOON AND INTO THE EVENING, EXPECT CONDITIONS TO IMPROVE
TO VFR FOR MOST AREAS WITH ISOLATED MVFR IN HEAVIER SHOWERS.
MOUNTAIN OBSCURATIONS WILL BE WIDESPREAD THIS MORNING WITH PARTIAL
OBSCURATIONS IN THE AFTERNOON. ALSO WITH THE FRONT MOVING INLAND
WINDS WILL GRADUALLY LOWER. HOWEVER EXPECT GUSTY WINDS TO
CONTINUE, ESPECIALLY FROM THE CASCADES EAST. /CC

&&

.MARINE...UPDATED 1045 PM PDT WED 22 OCT 2014...WINDS HAVE
LOWERED BEHIND A FRONT BUT SEAS WILL REMAIN ELEVATED AND HAZARDOUS
TO SMALL CRAFT EARLY THIS MORNING THROUGH TONIGHT DUE TO WESTERLY
SWELL. THERE WILL BE A LULL IN BOTH WINDS AND SEAS FRIDAY. MODELS
ARE COMING INTO BETTER AGREEMENT WITH THE FRIDAY NIGHT/SATURDAY
SYSTEM. ALL SHOW A DEEPENING SURFACE LOW MOVING NORTHWARD ALONG
THE 130 W BENCHMARK FRIDAY NIGHT THEN NORTHEASTWARD INSIDE 130 W
SATURDAY. VERY STRONG SOUTH WINDS WILL DEVELOP AHEAD OF THIS
SYSTEM FRIDAY NIGHT WITH HIGH END GALE CONDITIONS AND POSSIBLE
STORM FORCE GUSTS SATURDAY. STAY TUNED FOR FURTHER UPDATES
REGARDING THIS POTENTIAL BIG WIND-MAKER. CONDITIONS WILL IMPROVE
THROUGH THE REMAINDER OF THE WEEKEND, AND AFTER ANOTHER BRIEF
ROUND OF CALMER WINDS AND SEAS, ANOTHER FRONT IS EXPECTED EARLY
NEXT WEEK. -SPILDE/CC

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 11 AM PDT THURSDAY FOR ORZ031.

CA...WIND ADVISORY UNTIL 11 AM PDT THURSDAY FOR CAZ081.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL
        8 AM PDT FRIDAY FOR PZZ350-356-370-376.
     GALE WARNING UNTIL 2 AM PDT THURSDAY FOR PZZ356-376.
     HAZARDOUS SEAS WARNING UNTIL 2 AM PDT THURSDAY FOR PZZ356-376.

$$

15/15/11




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.